JP4700401B2 - Developing device and electrophotographic image forming apparatus - Google Patents

Description

  The present invention relates to a developing device and an electrophotographic image forming apparatus including the developing device, and more particularly to a developing device having an improved rotating structure of a developing roller and an electrophotographic image forming apparatus including the developing device.

  In general, an electrophotographic image forming apparatus such as a laser printer or a digital copying machine scans light on a photosensitive medium charged to a predetermined potential to form an electrostatic latent image on the outer peripheral surface thereof, thereby This is a device that prints an image by putting toner, which is a developer, into a latent image and developing it into a visible image, and then transferring and fixing it onto a sheet. Such an electrophotographic image forming apparatus includes a developing unit that is detachably mounted inside the main body. The developing device includes a photosensitive medium on which an electrostatic latent image is formed on an outer peripheral surface, and a developing roller that provides toner to the outer peripheral surface of the photosensitive medium. This developing device contains toner therein and is replaced with a new one when the toner is consumed.

  On the other hand, during the printing process, the power for rotating the photosensitive medium and the developing roller is transmitted from a motor inside the main body. When the developing device is mounted inside the main body, the motor and the developing device are connected by a predetermined coupling means (connecting means) in order to transmit the power. FIG. 1 is an exploded perspective view showing an example of coupling means for connecting a developing device and a motor in a conventional electrophotographic image forming apparatus.

  Referring to FIG. 1, the coupling means is linked to a triangular protrusion 11 projecting in the longitudinal direction of the photosensitive drum 5 from the tip of the rotating shaft 10 of the photosensitive drum 5 as a photosensitive medium, and a motor (not shown). And a power transmission shaft 20 provided with a triangular groove 22 that rotates and engages with the triangular protrusion 11. The power transmission shaft 20 is configured to advance and retreat in the direction of the arrow in conjunction with an opening / closing operation of a door (not shown) of an image forming apparatus that is opened for detachment of the developing unit including the photosensitive drum 5. . The photosensitive drum 5 has a rotation shaft 10 inserted into an opening 17 formed in the developing device frame 15 and is rotatably mounted on the developing device frame 15. Therefore, the triangular protrusion 11 is , Exposed to the outside of the developing device frame 15.

  When the door is opened to mount the developing device inside the main body of the image forming apparatus, the power transmission shaft 20 moves backward. When the developing unit is inserted and mounted inside the main body of the image forming apparatus and the door is closed, the power transmission shaft 20 moves forward again, and the triangular protrusion 11 of the photosensitive drum 5 is inserted into the triangular groove 22. The motor inside the main body and the photosensitive drum 5 inside the developing device are connected. As a result, when the motor rotates in accordance with a printing instruction, the power is transmitted and the photosensitive drum 5 rotates.

  On the other hand, a gear portion 7 is provided on the outer periphery of the longitudinal end of the photosensitive drum 5. Although not shown, gear portions that mesh with the gear portion 7 of the photosensitive drum are also provided on the outer peripheral portions of the developing roller, the supply roller, and the agitator in the longitudinal direction inside the developing device. Therefore, when the photosensitive drum 5 rotates, the developing roller, supply roller, and agitator also rotate in conjunction with each other.

JP 2002-341696 A

  However, in the conventional developing device, as described above, the power transmission shaft 20 that moves forward and backward in association with the opening and closing of the door has a complicated structure, requires many parts, has a high production cost, and is easy to assemble. There was a problem of being bad. On the other hand, the developing roller that rotates while being geared to the photosensitive drum 5 causes minute fluctuations in the rotational speed of the developing roller according to the processing accuracy of the gear portion 7 of the photosensitive drum 5 and the engagement of the developing roller gear portion. Thus, there is a problem that jitter may be formed in the printed image.

  Further, the developing roller meshed with the photosensitive drum 5 by the gear receives a force in a direction in which the distance from the photosensitive drum 5 is separated or approached by the rotation of the photosensitive drum 5. Therefore, the development gap between the outer peripheral surface of the photosensitive drum 5 and the outer peripheral surface of the developing roller is different from the set value, and as a result, there is a problem that the print quality is affected.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to improve the printing structure by improving the rotating structure of the developing roller mounted on the developing device frame. Another object of the present invention is to provide a new and improved developing device and an electrophotographic image forming apparatus having the same.

In order to solve the above-described problems, according to an aspect of the present invention, there is provided a developing device including a developing device frame that contains a developer, and a developing roller that is rotatably disposed inside the developing device frame. The The developing device includes a developing roller end portion and a gear member between the developing device frame and the developing roller, and a disc is sandwiched between the developing roller end portion and the gear member,
Coupling means for connecting the developing device frame and the developing roller is further provided. The coupling means is rotatably mounted on the developing device frame, and is provided at the end of the developing roller and a gear member that meshes with and rotates with a first gear provided outside the developing device to transmit rotational power. , A developing roller end portion that rotates in the same rotation direction with reference to the same rotation axis as the gear member, and the gear member has a first protrusion that protrudes toward the developing roller. A second protrusion protruding toward the gear member is provided at the end of the developing roller, and the first protrusion and the second protrusion are provided between the gear member and the end of the developing roller. If a disk that engages with the protrusion is interposed and the gear member rotates, the disk rotates by the rotation of the first protrusion, and further, the development by the rotation of the second protrusion accompanying the rotation of the disk. B La end is characterized in that is configured to rotate.

  The gear member may include a gear portion that meshes with the first gear, and the gear portion may be exposed to the outside of the developing device frame through the developing device frame.

  The gear member is provided with a first protrusion protruding toward the developing roller, and the developing roller end portion is provided with a second protrusion protruding toward the gear member, and the gear member and the developing roller end portion are provided. Between the first protrusion and the second protrusion is interposed between them, and if the gear member rotates, the disk is rotated by the rotation of the first protrusion, and further, the second is accompanied by the rotation of the disk. The end of the developing roller may be rotated by the rotation of the protrusion.

  Further, a supply roller for supplying the developer to the developing roller and an agitator for stirring the developer are provided inside the developing device frame. The supply roller and the agitator are gear-coupled to the developing roller, and the developing roller is If it rotates, you may be comprised so that it may rotate together.

  In addition, a photosensitive medium on which an electrostatic latent image corresponding to an image to be printed is formed by optical scanning is provided inside the developing device frame, and the photosensitive medium is provided outside the developing device to transmit rotational power. The second gear may be configured to mesh with and rotate.

In order to solve the above problems, according to another aspect of the present invention, a photosensitive medium on which an electrostatic latent image corresponding to an image to be printed is formed by optical scanning, and a developer is supplied to the photosensitive medium. An electrophotographic image forming apparatus including a developing device that develops a visible image is provided. In the image forming apparatus, the developing unit includes a developing unit frame that contains a developer, a developing roller that is rotatably disposed inside the developing unit frame, and a developing roller between the developing unit frame and the developing roller. And a coupling means for connecting the developing device frame and the developing roller by sandwiching a disk between the developing roller end and the gear member. The coupling means is rotatably mounted on the developing device frame, and is provided at the end of the developing roller and a gear member that meshes with and rotates with a first gear provided outside the developing device to transmit rotational power. , A developing roller end portion that rotates in the same rotation direction with reference to the same rotation axis as the gear member, and the gear member has a first protrusion that protrudes toward the developing roller. A second protrusion protruding toward the gear member is provided at the end of the developing roller, and the first protrusion and the second protrusion are provided between the gear member and the end of the developing roller. If a disk that engages with the protrusion is interposed and the gear member rotates, the disk rotates by the rotation of the first protrusion, and further, the development by the rotation of the second protrusion accompanying the rotation of the disk. B La end is characterized in that is configured to rotate.

  The gear member may include a gear portion that meshes with the first gear, and the gear portion may be exposed to the outside of the developing device frame through the developing device frame.

  The gear member is provided with a first protrusion protruding toward the developing roller, and the developing roller end portion is provided with a second protrusion protruding toward the gear member. A disk that engages with the first protrusion and the second protrusion is interposed between the first protrusion and the second protrusion. If the gear member rotates, the disk rotates due to the rotation of the first protrusion. It may be configured such that the end of the developing roller is rotated by the rotation of the two protrusions.

  Further, a supply roller for supplying the developer to the developing roller and an agitator for stirring the developer are provided inside the developing device frame. The supply roller and the agitator are gear-coupled to the developing roller, and the developing roller If they rotate, they may be configured to rotate together.

  Further, the photosensitive medium may be arranged inside the developing device frame, and the photosensitive medium may be configured to mesh with a second gear provided outside the developing device and rotate to transmit rotational power. .

  The first gear and the second gear may be configured to be driven by different motors.

  Moreover, you may make it further provide the buffer means which supports a 1st gear so that the damage by the collision with the said 1st gear and a gear member may be prevented.

  Furthermore, the buffer means may include a bracket that rotatably supports the first gear and a spring that elastically supports the bracket.

  In the developing device as described above, it is possible to improve the printing structure by improving the rotating structure of the developing roller. For example, the means for transmitting the rotational force to the developing device is not linked with the opening / closing of a door that is opened / closed when the developing device is attached / detached. For this reason, the structure of the developing device can be simplified and the number of parts can be reduced as compared with the conventional case. Therefore, the assemblability is improved and the production cost can be reduced.

  Further, since the developing device frame and the developing roller are connected by the coupling means, the developing roller can rotate at a constant speed, and the developing gap between the developing roller and the photosensitive drum can be maintained constant. This improves the print quality.

  As described above, according to the present invention, by connecting the developing device frame and the developing roller by the coupling means, the developing roller can be rotated at a constant speed and the developing gap can be kept constant, so that the printing quality can be improved. .

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
First, a developing device according to a first embodiment of the present invention and an electrophotographic image forming apparatus including the developing device will be described.

  FIG. 2 is a cross-sectional view schematically showing the electrophotographic image forming apparatus 100 according to the present embodiment. FIG. 3 shows the development roller 140 inside the developing device 120 shown in FIG. 4 is an exploded perspective view showing coupling means connected to a motor external to the developing device 120. FIG. 4 is an exploded perspective view showing the photosensitive drum 130 inside the developing device 120 shown in FIG. 5 is a cross-sectional view showing a mechanism for transmitting power to the developing roller 120 and the photosensitive drum 130 shown in FIG.

  Referring to FIG. 2, the electrophotographic image forming apparatus 100 according to the present embodiment includes a housing 101, an optical scanning unit 110 and a developing device 120 provided inside the housing 101.

  The optical scanning unit 110 scans the light L corresponding to an image to be printed (print target image) onto a photosensitive medium 130 described later, and forms an electrostatic latent image on the outer peripheral surface of the photosensitive medium 130. The optical scanning unit 110 includes a light source (not shown) that emits a laser beam L and a beam deflector that deflects the laser beam L emitted from the light source. As the beam deflector, for example, as shown in FIG. 2, a polygon mirror 112 that scans light while being rotated by a driving source is employed. As the beam deflector, a hologram disk (not shown) that deflects and scans light by diffracting and scanning with a hologram pattern formed on the disk surface is used instead of the polygon mirror 112. There is also.

  The developing device 120 is a cartridge type that is detachably mounted inside the housing 101. In the developing device 120, a photosensitive medium 130, a charging roller 139, a waste toner cleaner 138, a developing roller 140, a doctor blade 158, a supply roller 160, and an agitator 162 are installed inside a developing device frame 122 that forms an exterior.

  Further, in the developing device frame 122, a waste toner storage space 123 in which the waste toner removed from the outer peripheral surface of the photosensitive medium 130 by the waste toner cleaner 138 is stored, and a toner storage in which toner as a developer is stored. A space 125 is provided. When the toner stored in the toner storage space 125 of the developing device 120 is exhausted, it is replaced with a new cartridge of the developing device 120. An openable and closable door 103 is provided on the upper side of the housing 101 so that the developing device 120 can enter the housing 101.

  The photosensitive medium 130 is composed of, for example, a photosensitive drum in which a photoconductive material layer is formed on the outer peripheral surface of a cylindrical metal drum by a method such as vapor deposition. The photosensitive drum 130 is charged to a predetermined potential through the charging roller 139, and as described above, an electrostatic latent image corresponding to the image to be printed is formed on the outer peripheral surface by the light irradiated from the optical scanning unit 110. Is done.

  The developing roller 140 transmits toner as a developer to the photosensitive drum 130 on which the electrostatic latent image is formed, and develops the electrostatic latent image into a visible toner image. The supply roller 160 supplies toner to the developing roller 140. The agitator 162 swings so that the toner in the toner storage space 125 does not harden. On the other hand, the doctor blade 158 regulates the thickness of toner supplied from the supply roller 160 and attached to the outer peripheral surface of the developing roller 140. The waste toner cleaner 138 peels off and removes the waste toner that is not transferred to the printing paper P but remains on the outer peripheral surface of the photosensitive drum 130. The waste toner removed by the waste toner cleaner 138 is accumulated in the waste toner storage space 123.

  The transfer roller 170 is installed so as to face the outer peripheral surface of the photosensitive drum 130. The visible toner image developed on the outer peripheral surface of the photosensitive drum 130 is a printing paper that passes between the transfer roller 170 and the photosensitive drum 130 by a transfer bias or a contact pressure between the photosensitive drum 130 and the transfer roller 170. Transferred to P.

  The fixing device 175 includes a heat roller 176 and a pressure roller 177 arranged to face each other. When the printing paper P to which the visible toner image has been transferred passes between the heat roller 176 and the pressure roller 177, the image is fixed to the printing paper P by thermocompression using heat and pressure.

  In addition, the electrophotographic image forming apparatus 100 includes pickup rollers 180 and 182 that pick up the printing paper P stacked on the first and second paper feeding cassettes 105 and 106 on the lower side of the housing 101 one by one. Each is provided. Further, the image forming apparatus 100 provides a transfer force to the picked-up printing paper P, and at a desired portion of the printing paper P before the printing paper P passes between the photosensitive drum 130 and the transfer roller 170. A paper aligner 190 that aligns the printing paper P so as to transfer the toner image is provided. In addition, the image forming apparatus 100 includes a paper discharge roller 179 that discharges the print paper P on which a predetermined image has been printed through the fixing device 175 to the paper discharge tray 102 outside the housing 101.

  The operation of the electrophotographic image forming apparatus 100 having the above configuration will be described as follows. The photosensitive drum 130 is charged to a predetermined potential through the charging roller 139, and in response to the light beam L scanned from the optical scanning unit 110, an electrostatic latent image corresponding to an image to be printed on the outer peripheral surface thereof. Is formed. The toner in the toner storage space 125 of the developing device 120 is stirred by the agitator 162 and supplied to the photosensitive drum 130 on which the electrostatic latent image is formed by the supply roller 160 and the developing roller 140, and the photosensitive drum 130. A visible toner image is developed on the outer peripheral surface of the toner. On the other hand, the printing paper P stacked on the top of the first or second paper feeding cassette 105, 106 is picked up by the pick-up roller 180 or 182 and fed and aligned by the paper aligner 190, and the photosensitive drum. It passes between 130 and the transfer roller 170. At this time, the visible toner image developed on the outer peripheral surface of the photosensitive drum 130 is transferred to the surface of the printing paper P facing the photosensitive drum 130. The visible toner image transferred to the printing paper P passes through the fixing device 175, is fixed on the printing paper P by heat and pressure, is transferred by the paper discharge roller 179, and is stacked on the paper discharge tray 102. The

  Referring to FIG. 3, the developing roller 140 rotatably disposed inside the developing device frame 122 is connected to the developing device frame 122 by coupling means. The coupling means includes, for example, a developing roller end portion 143, a gear member 150, and a disk 145 interposed between the developing roller end portion 143 and the gear member 150.

  The gear member 150 is rotatably accommodated in an accommodation hole 128 formed in the developing device frame 122. The accommodation hole 128 is a circular recess formed on the surface of the developing device frame 122 on the developing roller side, and an opening 127 having a smaller diameter than the accommodation hole 128 is formed through the center of the bottom portion thereof. Further, the gear member 150 includes a gear portion 154 formed with a gear mesh, and the gear portion 154 protrudes outside the developing device frame 122 through an opening 127 formed in the developing device frame 122. . The gear member 150 includes a pair of first protrusions 152 protruding toward the developing roller 140. The pair of first protrusions 152 are arranged so as to be separated from each other at positions close to the outer peripheral portion on the circular side surface of the gear member 150 on the developing roller 140 side, for example.

  The developing roller end 143 may be manufactured separately from the developing roller 140, for example, and may be fixed to the tip of the developing roller 140, or may be formed by processing the tip of the developing roller 140. The developing roller end portion 143 includes a pair of second protrusions 144 protruding toward the gear member 150. The pair of second protrusions 144 are arranged, for example, so as to be separated from each other at positions close to the outer peripheral portion on the circular side surface of the developing roller end portion 143 on the gear member 150 side.

  The disk 145 has slots 146 and 147 formed from the outer peripheral surface thereof toward the center. The slots include a pair of first slots 146 that engage with the pair of first protrusions 152 of the gear member 150 and a pair of second slots 147 that engage with the pair of second protrusions 144 of the developing roller end portion 143. It is divided.

  The disk 145 is connected to the gear member 150 and the developing roller end 145 so that the first slot 146 of the disk 145 is engaged with the first protrusion 152 and the second slot 147 is engaged with the second protrusion 144. Further, the gear member 150 is fitted into the receiving hole 128 so that the gear portion 154 of the gear member 150 passes through the opening 127 of the developing device frame 122. Thus, the coupling means is assembled by sandwiching the disk 145 and the gear member 150 between the developing device frame 122 and the developing roller 140. When the gear member 150 of the coupling means assembled in this way rotates, the first protrusion 152 rotates and the disk 145 rotates, and the rotation of the disk 145 rotates the second protrusion 144 to develop. The roller end 143 rotates. As a result, when the gear member 150 rotates, the disk 145 and the developing roller end portion 143 also rotate in the same rotation as the rotation axis of the gear member 150 indicated by a two-dot chain line in conjunction with the gear member 150. Rotate around the axis and rotate in the same direction.

  On the other hand, a gear portion 141 is formed on the outer peripheral portion at the tip of the developing roller 140. The gear portion 141 is for gear connection between the developing roller 140, the supply roller 160 and the agitator 162.

  Referring to FIG. 4, the photosensitive drum 130 has a rotating shaft 131 projecting at the tip thereof rotatably engaged with a receiving hole 126 formed in the developing device frame 122, so that the photosensitive drum 130 is placed inside the developing device frame 122. Installed. A gear portion 132 is formed on the outer peripheral portion at the tip of the photosensitive drum 130.

  As can be seen with reference to FIG. 5, when the developing device 120 is mounted inside the housing 101, the gear portion 154 of the gear member 150 is engaged with the first gear 201, and the gear portion 132 of the photosensitive drum 130 is engaged with the second gear. Engage with 203. The first gear 201 and the second gear 203 are for transmitting rotational force to the developing roller 140 and the photosensitive drum 130, respectively.

  When the developing device 120 is mounted inside the housing 101, the first gear 201 is supported by a buffer means in order to prevent damage to both due to the collision between the gear portion 154 and the first gear 201. The buffer means includes, for example, a bracket 215 that rotatably supports the first gear 201 and a spring 217 that elastically supports the bracket 215.

  When the developing device 120 is inserted into the housing 101 and mounted, if the first gear 201 hits the gear portion 154, the spring 217 is pushed by the gear portion 154 and contracts. Damage to the portion 154 and the first gear 201 can be prevented. When the developing device 120 is mounted on the housing 101, the spring 217 presses the bracket 215 toward the gear portion 154, so that the first gear 201 and the gear portion 154 are in close contact with each other. .

  The bracket 215 also rotatably supports a connection gear 212 that meshes with the first gear 201. The connecting gear 212 meshes with a shaft 210 of a developing roller drive motor (not shown). Therefore, when the shaft 210 of the developing roller drive motor rotates, the rotational force is sequentially transmitted to the connecting gear 212, the first gear 201, and the gear portion 154 of the gear member 150, and further, the gear member 150, the disk 145, and so on. , And the developing roller end portion 143 sequentially, the developing roller 140 rotates.

  The gear member 150 rotates while meshing with the first gear 201, but the developing roller 140 is rotated by the coupling means formed from the gear member 150, the disk 145 and the developing roller end portion 143 as described above. Therefore, unlike the conventional case where the developing roller is rotated by meshing the gear between the photosensitive drum and the developing roller, in this embodiment, the rotational speed of the developing roller 140 is finely oscillated and the size of the developing gap is reduced. A minute change can be prevented.

  The second gear 203 meshes with a shaft 205 of a main motor (not shown) that drives a roller on the transfer path of the printing paper P. Accordingly, if the main motor shaft 205 rotates while the developing device 120 is mounted inside the housing 101, the rotational force is sequentially transmitted to the second gear 203 and the photosensitive drum gear portion 132, and the photosensitive drum photosensitive portion 132 is exposed. The drum 130 rotates.

  The shaft 205 of the main motor keeps rotating until the printing paper P is picked up by the pick-up roller 180 or 182 and is discharged out of the housing 101 by the paper discharge roller 179, so that the photosensitive drum 130 rotates in the meantime. Keep doing. However, it is not necessary to rotate the developing roller 140 except when developing a visible toner image on the outer peripheral surface of the photosensitive drum 130. Therefore, the shaft 210 of the developing roller drive motor is used only when developing a visible toner image. Controlled to rotate. In this way, the agitator 162 geared to the developing roller 140 also rotates only in a short time compared to the conventional case. Accordingly, when the toner is agitated for a long time, external additives such as a charging aid and wax coated on the toner are separated, and so-called “toner stress” that reduces the quality of the printed image is reduced.

  The developing device 120 according to the present embodiment and the electrophotographic image forming apparatus 100 including the same have been described above. According to the developing device 120, the rotation structure of the developing roller 140 is improved and the following effects are obtained.

  First, since the means for transmitting the rotational force to the developing device 120 can be made not to be linked with the opening and closing of the door 103, the structure can be simplified and the number of parts can be reduced as compared with the prior art. Therefore, the assemblability is improved and the production cost can be reduced.

  Second, since the developing device frame 122 and the developing roller 140 are coupled by the coupling means, the developing roller 140 can rotate at a constant speed, and development between the outer peripheral surface of the photosensitive drum 130 and the outer peripheral surface of the developing roller 140 is possible. The gap can also be kept constant. This improves the print quality.

  Thirdly, since the agitator 162 operates only for a short time compared to the conventional case, the toner stress is reduced.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The present invention is applicable to a developing device and an electrophotographic image forming apparatus including the developing device.

FIG. 6 is an exploded perspective view showing an example of coupling means for connecting a developing device and a motor in a conventional electrophotographic image forming apparatus. 1 is a cross-sectional view schematically showing an electrophotographic image forming apparatus according to a first embodiment of the present invention. FIG. 3 is an exploded perspective view showing coupling means for connecting a developing roller inside the developing unit shown in FIG. 2 with a motor outside the developing unit. FIG. 3 is an exploded perspective view showing a photosensitive drum inside the developing device shown in FIG. 2. FIG. 3 is a cross-sectional view illustrating a power transmission mechanism to a developing roller and a photosensitive drum illustrated in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Electrophotographic image forming apparatus 101 Housing 102 Discharge stand 103 Door 105 1st paper feed cassette 106 2nd paper feed cassette 110 Optical scanning unit 112 Polygon mirror 120 Developer 122 Developer frame 123 Waste toner storage space 125 Toner storage Space 130 Photosensitive drum 138 Waste toner cleaner 139 Charging roller 140 Developing roller 158 Doctor blade 160 Supply roller 162 Agitator 170 Transfer roller 175 Fixing unit 176 Heat roller 177 Pressure roller 179 Paper discharge rollers 180 and 182 Pickup roller 190 Paper aligner

Claims (11)

In a developing device comprising a developing device frame for containing a developer, and a developing roller rotatably disposed inside the developing device frame,
Between the developing roller and the developing device frame, a developing roller end portion includes a gear member, by sandwiching the disc between the gear member and the developing roller end portion, the developing and the developing device frame A coupling means for coupling the roller;
The coupling means includes
A gear member rotatably mounted on the developing device frame and meshed with a first gear provided outside the developing device for transmitting rotational power; and
A developing roller end that is provided at an end of the developing roller and rotates in the same rotational direction with respect to the same rotational axis as the gear member in conjunction with the gear member;
With
The gear member is provided with a first protrusion protruding toward the developing roller,
A second protrusion protruding toward the gear member is provided at the end of the developing roller,
Between the gear member and the end portion of the developing roller, a disk that engages with the first protrusion and the second protrusion is interposed,
If the gear member rotates, the disk rotates due to the rotation of the first protrusion,
The developing device, wherein the developing roller end portion is rotated by the rotation of the second protrusion accompanying the rotation of the disk . The gear member includes a gear portion meshing with the first gear;
The developing device according to claim 1, wherein the gear portion penetrates the developing device frame and is exposed to the outside of the developing device frame. Inside the developing device frame, a supply roller for supplying a developer to the developing roller and an agitator for stirring the developer are provided,
The supply roller and the agitator gear is connected to the developing roller, the developing roller is characterized in that it is configured to rotate together when rotated, the developing device according to claim 1 or 2. A photosensitive medium on which an electrostatic latent image corresponding to an image to be printed is formed by optical scanning is provided inside the developing device frame,
The photosensitive medium, for rotation power transmission, characterized in that said configured to rotate in mesh with the second gear provided outside of the developing device, to any one of claims 1 to 3 The developing device described. An electrophotographic image forming apparatus comprising: a photosensitive medium on which an electrostatic latent image corresponding to an image to be printed is formed by optical scanning; and a developing unit that supplies a developer to the photosensitive medium and develops it into a visible image. ,
The developer is
A developer frame containing the developer;
A developing roller rotatably disposed inside the developer frame;
Between the developing roller and the developing device frame, a developing roller end portion includes a gear member, by sandwiching the disc between the gear member and the developing roller end portion, the developing and the developing device frame Coupling means for connecting the roller;
With
The coupling means includes
A gear member rotatably mounted on the developing device frame and meshed with a first gear provided outside the developing device for transmitting rotational power; and
A developing roller end that is provided at an end of the developing roller and rotates in the same rotational direction with respect to the same rotational axis as the gear member in conjunction with the gear member;
With
The gear member is provided with a first protrusion protruding toward the developing roller,
A second protrusion protruding toward the gear member is provided at the end of the developing roller, and the first protrusion and the second protrusion are engaged between the gear member and the end of the developing roller. Disk to intervene,
If the gear member rotates, the disk rotates due to the rotation of the first protrusion,
An electrophotographic image forming apparatus, wherein the developing roller end portion is rotated by rotation of the second protrusion accompanying rotation of the disk . The gear member includes a gear portion meshing with the first gear;
The electrophotographic image forming apparatus according to claim 5 , wherein the gear portion passes through the developing device frame and is exposed to the outside of the developing device frame. Inside the developing device frame, a supply roller for supplying a developer to the developing roller and an agitator for stirring the developer are provided,
The electrophotographic image according to claim 5 or 6 , wherein the supply roller and the agitator are gear-coupled to the developing roller and are configured to rotate together when the developing roller rotates. Forming equipment. The photosensitive medium is disposed inside the developing device frame,
The photosensitive medium, for rotation power transmission, characterized in that said configured to rotate in mesh with the second gear provided outside of the developing device, to any one of claims 5 to 7 The electrophotographic image forming apparatus described. 9. The electrophotographic image forming apparatus according to claim 8 , wherein the first gear and the second gear are configured to be driven by different motors. 10. The shock absorber according to claim 5 , further comprising a buffer unit that supports the first gear so as to prevent damage due to a collision between the first gear and the gear member. 11 . An electrophotographic image forming apparatus. The buffer means is:
A bracket for rotatably supporting the first gear;
A spring that elastically supports the bracket;
The electrophotographic image forming apparatus according to claim 10 , further comprising:

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